Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2014 Sep-Oct;19(5):88-96.
doi: 10.1590/2176-9451.19.5.088-096.oar.

Rapid maxillary expansion effects: an alternative assessment method by means of cone-beam tomography

Camilo Aquino Melgaço  1 , José Columbano Neto  2 , Estela Maris Jurach  3 , Matilde da Cunha Gonçalves Nojima  4 , Eduardo Franzotti Sant'Anna  4 , Lincoln Issamu Nojima  4
Affiliations
Randomized Controlled Trial

Rapid maxillary expansion effects: an alternative assessment method by means of cone-beam tomography

Camilo Aquino Melgaço et al. Dental Press J Orthod. 2014 Sep-Oct.

Abstract
in English, Portuguese

Introduction: This study aims to develop a method to assess the changes in palatal and lingual cross-sectional areas in patients submitted to rapid maxillary expansion (RME).

Methods: The sample comprised 31 Class I malocclusion individuals submitted to RME and divided into two groups treated with Haas (17 patients) and Hyrax (14 patients) expanders. Cone-beam computed tomography scans were acquired at T0 (before expansion ) and T1 (six months after screw stabilization). Maxillary and mandibular cross-sectional areas were assessed at first permanent molars and first premolars regions and compared at T0 and T1. Mandibular occlusal area was also analyzed.

Results: Maxillary cross-sectional areas increased in 56.18 mm2 and 44.32 mm2 for the posterior and anterior regions. These values were smaller for the mandible, representing augmentation of 40.32 mm2 and 39.91 mm2 for posterior and anterior sections. No differences were found when comparing both expanders. Mandibular occlusal area increased 43.99mm2 and mandibular incisors proclined. Increments of 1.74 mm and 1.7 mm occurred in mandibular intermolar and interpremolar distances. These same distances presented increments of 5.5 mm and 5.57 mm for the maxillary arch.

Conclusion: Occlusal and cross-sectional areas increased significantly after RME. The method described seems to be reliable and precise to assess intraoral area changes.

INTRODUÇÃO:: o presente estudo teve como objetivo desenvolver um método para avaliar as mudanças nas áreas transversais palatinas e linguais em pacientes submetidos à expansão rápida da maxila (ERM).

MÉTODOS:: a amostra foi composta por 31 indivíduos com má oclusão Classe I de Angle, submetidos a ERM e divididos em dois grupos, tratados com expansores tipo Haas (17 pacientes) e de Hyrax (14 pacientes). Tomografias computadorizadas de feixe cônico foram adquiridas em T0 e T1 (antes da expansão e seis meses após a estabilização do parafuso). Áreas transversais da maxila e mandíbula foram avaliadas nas regiões de primeiros molares permanentes e pré-molares e comparadas entre T0 e T1. A área oclusal mandibular também foi analisada.

RESULTADOS:: as áreas transversais maxilares aumentaram 56,18mm2 e 44,32mm2 para regiões posterior e anterior, respectivamente. Esses valores foram menores para mandíbula, representando aumentos de 40,32mm2 e de 39,91mm2 para as seções anterior e posterior. Não foram encontradas diferenças quando se comparam os dois expansores. A área oclusal mandibular aumentou 43,99mm2 e incisivos inferiores vestibularizaram. Incrementos de 1,74mm e 1,7mm ocorreram entre as distâncias intermolares e interpré-molares inferiores. Essas mesmas distâncias apresentaram incrementos de 5,5mm e de 5,57mm para maxila.

CONCLUSÃO:: as áreas transversais avaliadas e oclusal de mandíbula aumentaram significativamente após a ERM. O processo descrito parece ser um método confiável e preciso para avaliar as mudanças das área intrabucais propostas.

PubMed Disclaimer

Figures

Figure 1
Figure 1. Head orientation based on axial, coronal and sagittal planes.
Figure 2
Figure 2. Maxillary measures: (MD) intermolar distance; (VDM) vertical displacement of molars and (PMA) posterior maxillary cross-sectional area. The same measures were performed for premolars.
Figure 3
Figure 3. A) Mandibular measures: (MD) intermolar distance; (VDM) vertical displacement of molars and (PMnA) posterior mandibular cross-sectional area. The same measures were performed for premolars. B) Mandibular occlusal area (MnOA) and mandibular occlusal contour (MnOC).
Figure 4
Figure 4. Blue and red landmarks are 1 cm apart. The total contour is 12 cm for both cases. However, differences are evident.
See this image and copyright information in PMC

References

    1. Adkins MD, Nanda RS, Currier GF. Arch perimeter changes on rapid palatal expansion. Am J Orthod Dentofacial Orthop. 1990;97(2):194–199. - PubMed
    1. Angell EC. Treatment of irregularities of the permanent or adult teeth. Dent Cosmos. 1860;1:540–544.
    1. Baccetti T, Franchi L, McNamara JA., Jr The cervical vertebral maturation (CVM) method for the assessment of optimal treatment timing in dentofacial orthopedic. Semin Orthod. 2005;11(3):119–129.
    1. Bazargani F, Feldmann I, Bondemark L. Three-dimensional analysis of effects of rapid maxillary expansion on facial sutures and bones. Angle Orthod. 2013;83(6):1074–1082. - PMC - PubMed
    1. Chung C-H, Font B. Skeletal and dental changes in the sagittal, vertical, and transverse dimensions after rapid palatal expansion. Am J Orthod Dentofacial Orthop. 2004;126(4):569–575. - PubMed

Publication types

MeSH terms